Dynamic event detection system and method

ABSTRACT

A method for dynamic event detection based on content from a set of social networking systems including receiving content from the set of social networking systems, identifying a plurality of content associated with a geofence, the content that was generated within a predetermined time period, determining feature values from the plurality of content for each of a set of features, determining an event probability for the geofence based on the feature values, and detecting an event within the geofence in response to the event probability exceeding a threshold event probability.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/643,958, filed 10 Mar. 2015, which is a continuation-in-part of U.S.application Ser. No. 14/574,966 filed 18 Dec. 2014, which claims thebenefit of U.S. Provisional Application No. 61/918,126, filed 19 Dec.2013, U.S. Provisional Application No. 62/060,407, filed 6 Oct. 2014,and U.S. Provisional Application No. 62/006,632, filed 2 Jun. 2014. Thisapplication is a continuation of U.S. application Ser. No. 14/643,958,filed 10 Mar. 2015, which is also a continuation-in-part of applicationU.S. application Ser. No. 14/501,436, filed 30 Sep. 2014, which is acontinuation-in-part of application Ser. No. 14/043,479, filed 1 Oct.2013, which claims the benefit of U.S. Provisional Application No.61/709,103, filed 2 Oct. 2012, U.S. Provisional Application No.61/782,687, filed 14 Mar. 2013, and U.S. Provisional Application No.61/784,809, filed 14 Mar. 2013. This application is a continuation ofU.S. application Ser. No. 14/643,958, filed 10 Mar. 2015, which is acontinuation-in-part of U.S. application Ser. No. 14/574,966 filed 18Dec. 2014, which is a continuation-in-part of U.S. application Ser. No.14/501,436, filed 30 Sep. 2014, which also claims the benefit of U.S.Provisional Application No. 61/885,322, filed 1 Oct. 2013, U.S.Provisional Application No. 61/918,126, filed 19 Dec. 2013, and U.S.Provisional Application No. 62/006,632, filed 2 Jun. 2014. All of theaforementioned applications are incorporated herein in their entiretiesby this reference.

TECHNICAL FIELD

This invention relates generally to the social media field, and morespecifically to a new and useful system and method of dynamic eventdetection in the social media field.

BACKGROUND

Social networking services provide a rich source of data for real-timeevent detection, particularly with the increased popularity of postinggeotagged content from mobile devices in real time. However, there areseveral problems posed by using social networking service content todetect events in real-time. First, the sheer volume and frequency ofcontent generated across each social networking service isimmense-attempting to analyze all the content generated across multiplesocial networking services in real time poses considerable processingand modeling challenges. Second, the social networking service contentis typically a mix of content with different focuses, ranging fromcontent that is relevant to an event (e.g., an image of the event focus)to content that is irrelevant to an event (e.g., content that is onlyrelevant to the user or the personal connections of the user),distributed across time and space. The volume of secondary content(e.g., content that is not about the event) tends to eclipse the primarycontent (e.g., content that is about the event), rendering detection ofthe beginning of an event difficult. Third, curation of the contentrelevant to the event poses an issue as well, as the event-associatedcontent can range from content about the event focus to content aboutspectators of the event. For example, content about the event focus canbe relevant to users interested about the event, while content about theevent spectators tends to be irrelevant to the users and dilutes thevalue of an event feed that is generated from the event-associatedcontent. Conversely, some entities can be interested in only the contentgenerated by spectators of the event (e.g., a sporting event or musicevent), while content about the event itself is irrelevant to the entityand dilutes the value of the content feed generated from the event- orgeographic region-associated content. The substantially real-time eventdetection can subsequently be used to notify users, used as a triggerevent for trading models or trading triggers in financial marketapplications, or used in any other suitable manner.

Thus, there is a need in the social networking services field to createa new and useful system and method for automatic, real-time eventdetection based on content generated on social networking systems.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic representation of an example of the method ofdynamic event detection.

FIG. 2 is a schematic representation of indexing content.

FIG. 3 is a schematic representation of determining a plurality ofcontent associated with a geofence.

FIG. 4 is a schematic representation of a variation of dynamic eventdetection based on feature values for the plurality of content.

FIG. 5 is a schematic representation of a variation of dynamic eventdetection based on feature values for each of the plurality of content.

FIG. 6 is a schematic representation of a variation of dynamic eventdetection based on feature values for the plurality of content, whereinthe plurality of content includes new content.

FIG. 7 is an example of an event listing ordered by event probability.

FIG. 8 is a schematic representation of a method including a first andsecond post-processing module.

FIG. 9 is a schematic representation of determining the event beginningand ending timestamp based on event probability.

FIG. 10 is an example of normalizing content volume based on typicalcontent volume for an airport and detecting an event based on thenormalized content volume.

FIG. 11 is an example of normalizing keyword ratios based on typicalkeyword ratios and detecting an event based on the normalized keywordratio.

FIG. 12 is a schematic representation of an example of plurality offeature distribution among the module feature sets.

FIG. 13 is a schematic representation of an example of post-processingthe values based on the event probability and a secondary set of featurevalues.

FIG. 14 is a schematic representation of an example of post-processingthe values based on a time series of event probabilities and a secondaryset of feature values.

FIG. 15 is a schematic representation of local popularity, globalpopularity, and spread.

FIG. 16 is a schematic representation of a first variation ofdetermining the geographic extent of an event based on geofence eventprobabilities.

FIG. 17 is a schematic representation of a second variation ofdetermining the geographic extent of an event based on the contentplurality associated with the event geofence.

FIG. 18 is a schematic representation of artificially maintaining thethreshold event probability.

FIG. 19 is a schematic representation of an example of user accountinteraction with the event detection system.

FIG. 20 is a schematic representation of a hyper-dimensional spacerepresentative of a set of feature values, wherein each geofence can beassociated with an imaginary geofence location within the space based onthe feature values associated with the geofence; wherein each geofencecan be associated with a typical location and/or region within the spacerepresentative of baseline or typical content for the geofence (unshadedcircles), wherein an event can be determined in response to theimaginary geofence location moving beyond a threshold distance, movingin a given direction or pattern of directions, or moving within thespace in any other suitable manner (shaded circles).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention.

As shown in FIG. 1, the system and method of dynamic event detectionincludes receiving content associated with a set of geofences S100,determining a set of feature values for each of the set of geofencesS200, and determining an event probability for the respective geofencebased on the set of feature values S300. The method can additionallyinclude analyzing feature values for adjacent geofences in response to ageofence event probability exceeding a threshold probability todetermine the geographic extent of the event. The method canadditionally include determining a characterization for the event,determine whether the event is of interest to a specific entity, ordetermine any other suitable information.

The method functions to automatically determine the probability that anevent is occurring within a predetermined geofence, in real time or innear-real time. The method preferably does so without reference to ascheduling database, and does not require data regarding a previouslyscheduled event. However, the method can determine the event based onpredetermined event information (e.g., a scheduled or known event), ordetermine the event or event probability in any other suitable manner.

The method confers several benefits over conventional event detectionmethods. First, the method leverages social networking system contentgenerated by users in real- or near-real time, such that events can bedynamically determined whether or not the event was pre-scheduled.Second, by determining values for a plurality of features from thegeofence content, the method enables rich contextualization of theevent. Third, by dynamically selecting the number of features that areconsidered by each processing module (model), the method expedites eventdetermination, categorization, or any other suitable event parameterdetermination. Fourth, by focusing on patterns, this method presents amore refined and accurate method of dynamically detecting events inreal- or near-real time. The patterns can be considered in lieu of or inaddition to parameter value averages (which rarely occur whenconsidering content parameters in real-time).

The method can be performed in whole or in part by an event detectionsystem supported by a computing system. The method can be performed by anative application on a user device, by a set of servers, by a browserapplication on a user device, or by any other suitable computing system.The computing systems can be stateless, stateful, or have any othersuitable configuration or property. The computing system preferablyreceives the content from and/or sends information to a remote secondarycomputing system associated with a social networking system, but canalternatively communicate with a user device or any other suitablecomputing system.

The content (i.e., electronic messages, posts, content, persistentcontent, persistent data, persistent posts, etc.) can include URLs,links, references, text, images, video clips, audio clips, and/or anyother suitable content. The content can additionally include metadata(i.e., an associated set of data properties). The metadata can include atimestamp, a geographic location (e.g., geotag, GPS coordinates, name ofgeographic location, etc.), a measure of location precision (e.g.,radius of uncertainty), a categorization or identifier for the mobiledevice generating the content, a user account identifier, the contentcapture mechanism (e.g., front camera or back camera), or any othersuitable parameter. The metadata is preferably representative of therespective parameters at the time of content creation or at the time thecontent was sent to the social networking system. The metadata ispreferably associated with the content at the time of content generation(e.g., when the content is created or when the content is sent to thesocial networking system), but can alternatively be associated with thecontent after social networking system receipt. While the contentpreferably includes information for all available parameters, thecontent can alternatively lack information for some parameters, such aslocation information. The content can lack the parameter information dueto a user preference restriction, due to the settings of the socialnetworking system (e.g., wherein the social networking system does notassociate location information with content), or for any other suitablereason. The content metadata can be associated with the content by theuser device creating the content, by the user account controllingcreation of the content, by a secondary user account, by the socialnetworking system receiving the content, by the computing system as partof the method, or associated with the content in any other suitablemanner.

Alternatively or additionally, the content can be associated with atime, location, or any other suitable parameter from the contents of theelectronic message. For example, a geographic location can be determinedfor and associated with the piece of content in the manner disclosed inSer. No. 14/043,479 filed 1 Oct. 2013, incorporated in its entirety bythis reference. However, any other suitable information can bedetermined and/or associated with the content in any other suitablemanner. In another example, the content can include a textual referenceto an event (e.g., through an event name, URL, or other suitable eventidentifier or reference), wherein the content can be associated with aknown event time and event location associated with the event. Inanother example, an image can be processed to extract location ortime-related metadata (e.g., exchangeable image file format data),extract a location from the image content (e.g., by image matching witha database), extract a location tag, or extract any other suitableinformation. In another example, the content can include text thatreferences a location (e.g., a location name) and/or a time (e.g., adate, a time, a duration from the time of content generation, etc.),wherein the referenced location and/or time are the associated locationand/or time. In another example, the content can reference a secondarysource (e.g., a secondary user account), wherein content authored by thesecondary user account includes a location and/or a time. The locationand/or time associated with the primary content can be the referencedlocation and/or time found in the content authored by the secondary useraccount.

The content is preferably generated by a user at a user device, whereinthe user device sends the content to the remote computing system or thesecondary remote computing system. However, the content can be generatedby any other suitable system. The user device can include one or moreserver computers, desktop computers, laptop computers, notebookcomputers, sub-notebook computers, netbook computers, netpad computers,set-top computers, handheld computers, Internet appliances, mobilesmartphones, tablet computers, personal digital assistants, video gameconsoles, vehicles, televisions, video players, tablets, or any othersuitable user device. The devices can be stand-alone or networked. Thedevice is preferably connected to the remote computing system (e.g., aserver system, cloud computing system, distributed computing system,mesh network, database, etc.), but can alternatively be connected to anyother suitable system. The device can be wirelessly connected to theremote computing system by a long range wireless connection, such asWiFi, a cellular network service, or any other suitable long rangewireless connection, or be connected by a short range connection, suchas radiofrequency, Bluetooth, near field, or any other suitable shortrange communication connection. Alternatively, the device can beconnected to the computing system by a wired connection, such as a LANline. The device can include a storage and/or memory device. The storageand/or memory device is one or more physical apparatuses used to storedata or programs on a temporary or permanent basis. The device caninclude volatile memory and requires power to maintain storedinformation. The device can additionally or alternatively includenon-volatile memory and retains stored information when the digitalprocessing device is not powered. The non-volatile memory can be flashmemory, dynamic random-access memory (DRAM), ferroelectric random accessmemory (FRAM), and phase-change random access memory (PRAM). The devicecan additionally or alternatively include a display to send visualinformation to a user. The display can be a cathode ray tube (CRT), aliquid crystal display (LCD), a thin film transistor liquid crystaldisplay (TFT-LCD), an organic light emitting diode (OLED) display, aplasma display, a video projector, a combination thereof, or be anyother suitable display. The OLED display can be a passive-matrix OLED(PMOLED) or active-matrix OLED (AMOLED) display. The device canadditionally or alternatively include an input device to receiveinformation from a user. The input device can be a keyboard, a pointingdevice (e.g., a mouse, trackball, track pad, joystick, game controller,stylus, etc.), a touch screen or a multi-touch screen, a microphone tocapture voice or other sound input, a video camera or other sensor tocapture motion or visual input, a combination thereof, or include anyother suitable input device.

The source of the content is preferably one or more online socialnetworking systems. Alternatively, the content source can includenon-social streams (e.g., weather sources, seismic records, etc.), newssources, blogs, or any other suitable content source. The method ispreferably capable of accessing and aggregating content from one or moresocial networking systems. Each social networking service is preferablyan online service, platform, or site that preferably includes aplurality of user accounts, wherein each user account is preferablyassociated with a unique user. Examples of social networking systemsinclude Facebook, Twitter, Linkedin, a digital group formed from linkedemail addresses, or any other suitable digital networking system. Thesocial networking system preferably stores the generated content, butcan alternatively facilitate persistent or temporary content storage onan external storage system. The content generated by the user account ispreferably arranged on a user page or content feed (i.e., contentstream) of the user account on the respective social networking system.The content feed can include user-generated content (e.g., contentposted by the user account to the social networking service). Thecontent feed for a user account can additionally or alternativelyinclude content posted by secondary user accounts to the socialnetworking system. The secondary user accounts can be user accounts thatare followed, friended, or otherwise directly connected to the useraccount. The content feed is preferably a time-ordered list (e.g.,ordered according to the time of generation), more preferably inverselytime-ordered with the most recent content at the top of the list, butcan alternatively be ordered according to popularity (e.g., asdetermined from the number of views of the content, number of actions onthe content, etc.), or ordered according to any other suitableparameter.

Each unique user can be associated with a user account on one or moresocial networking services. The method can aggregate the contentassociated with the multiple user accounts that are associated with auser. The user preferably indicates the user account associated with theuser (e.g., usernames) for each of the social networking services towhich the user belongs on the aggregation system, such as by enteringand/or signing into each social networking service through theaggregation system (e.g., native application or browser application)that performs the method. However, user accounts that are associatedwith the user across multiple social networking services can beotherwise determined.

A location can be a set of geographic coordinates (e.g., latitude andlongitude), a place name (e.g., county, city, landmark, intersection,etc.), a physical street address, distance from a given location,presence within a specified radius from a given location, a graphicaldepiction on a map, a polygon, a geofence, or any other suitablelocation expression. Geolocation can involve geocoding to findassociated latitude and longitude from other geographic data.Geolocation can additionally or alternatively involve reverse geocodingto back code latitude and longitude coordinates to a readable address orplace name. Geolocation can additionally or alternatively includedetermining the location based on the content of a post (e.g., fromtext, images, sounds, etc. within the post). The location can bedetermined based on GPS coordinates provided by a device, triangulationbetween mobile phone towers and public masts (e.g., assistive GPS),Wi-Fi connection location, WHOIS performed on IP address or MAC address,GSM/CDMA cell IDs, location information self-reported by a user, ordetermined in any other suitable manner.

A geofence can be a virtual representation of a geographic region,wherein the geographic region can encompass one or more geographiclocations. Alternatively, the method can be performed with a set ofspacefences, which can define a three-dimensionally limited space to bemonitored. Each geofence preferably includes an imaginary boundaryenclosing a geographic region, wherein the boundary includes a set ofimaginary segments forming a closed loop encircling the geographicregion. However, the boundary can alternatively include a circle orother shape defined relative to a geographic location (e.g., a centerpoint), or be defined in any other suitable manner. The segments arepreferably linear segments, but can alternatively be curved or otherwisedefined. The boundary can form a geometric shape (e.g., a polygonalshape) and is preferably non-circular, but can alternatively define acircle or any other suitable shape.

The geographic region enclosed by the geofence preferably encompassesone or more geographic locations, but can alternatively cover any othersuitable geographic area. Examples of geographic regions include solarsystems, a surface of an entire planet, a planet volume, continents,countries, states, counties, cities, communities, buildings, and rooms.The geographic region preferably encompasses one or more geographiclocations (e.g., geographic locations, event locations, physicallocations, etc.), wherein a geographic location can be identified by avenue name, a user-defined name (e.g., “home”), a set of GPScoordinates, a set of latitude and longitude coordinates, a set ofwireless cell tower triangulation information, an address, or any othersuitable identifier for a geographic location.

The shape and size of the geofences are preferably predetermined, butcan be dynamically determined. The geofences can be predetermined,automatically determined (e.g., based on feature values, contentparameters, etc.), determined by a user, determined by a plurality ofusers (e.g., wherein the boundary is set or stored within the systemafter a threshold number of users select the boundary, within apredetermined accuracy threshold), randomly determined, determined basedon physical barriers (e.g., run along a wall, etc.), determined based onpolitical delineations (e.g., along a city border, country border,etc.), determined based on third party reference points (e.g., celltower coverage areas, etc.), be predetermined geographic increments(e.g., 150 m by 150 m squares), or determined in any other suitablemanner. The geofences can be entered by an administrator (e.g., a userwith administrator permissions), determined when a threshold number ofusers have entered the same geofence (within a given degree ofvariability) within a threshold period of time, determined based onhistorical content generation densities over space (e.g., wherein thegeofence is defined by the locations at which the content density fallsbelow a threshold value), or defined in any other suitable manner.

Each geofence preferably includes a single boundary, such that ageofence encloses a continuous geographic region within the respectiveboundary. However, the geofence can include multiple boundaries, whereinthe boundaries are preferably nested (e.g., such that the geofenceencloses an annular region or a region is excluded from the geofencedregion). Boundaries independently enclosing separate or overlappinggeographic regions are preferably considered separate geofences, but canalternatively be considered part of the same geofence.

Each geofence can be associated with an identifier. The identifier canbe a geographic location within the geofence, a name of a venue withinthe geofence (e.g., wherein the venue name can be globally or locallyunique or non-unique), the name of a political subdivision wholly orpartially within the geofence (e.g., a neighborhood name, city name,etc.), the name of an event associated with the geofence, or be anyother suitable identifier.

Each geofence can additionally be associated with a normalizationfactor, which functions to normalize the feature values that aredetermined for each geofence. The normalization factor can be a scalarvalue, a vector, a pattern, or any other suitable normalization factor.The normalization value can be a baseline value, average value, or anyother suitable value for a feature or set thereof. The normalizationpattern can be described by a matrix, point in a hyper-dimensionalspace, density surface, or any other suitable means. In one example, ageofence in Times Square, New York can be associated with a highervolume of content, and therefore have a different normalization patternthan a geofence in upstate New York. The normalization factor ispreferably determined based on historic content generation in thegeographic location (e.g., based on historic content data), but canalternatively be determined in any other suitable manner.

A plurality of geofences is preferably determined (e.g., predeterminedor dynamically determined), but a single geofence can alternatively bedetermined. The geofences of the plurality can be overlapping, entirelyseparate, contiguous, or otherwise arranged. The overlapping geofencescan be nested (inclusive), wherein a first geofence entirely enclosesthe geographic region enclosed by a second geofence. The nestedgeofences can be concentric, offset, or otherwise arranged. Theplurality of geofences can include multiple sets of nested geofences,wherein each set can include multiple tiers of geofences. The geofenceswithin each tier can be overlapping, entirely separate, contiguous, orotherwise related. In one example, the plurality of geofences caninclude a geofence for a state, a geofence for a city within the state,a geofence for a neighborhood within the city, and a geofence for avenue within the neighborhood, wherein content for all of the previouslymentioned geofences can be simultaneously monitored. Alternatively, theoverlapping geofences can encompass a shared geographic location oroverlap in any other suitable manner. However, the geofences can beorganized or defined in any other suitable manner.

In a first variation of the method, the geofences have substantially thesame shape, are contiguous with adjacent geofences (e.g., share aborder), are non-overlapping, and cooperatively cover a substantiallycontiguous geographic region. In a specific variation, the geofencescooperatively form a grid or other matrix overlaid over the geographicregion. In a specific example, each geofence is 150 m×150 m, but canalternatively be larger or smaller. In a second variation of the method,the system includes overlapping geofence tiers, wherein each geofence ofa higher-level tier encompasses one or more geofences of a lower-leveltier. In a third variation of the method, the shape, size, or any othersuitable boundary parameter is determined based on the contentfrequency, density, or other content parameter. In a fourth variation ofthe method, the geofences can be determined based on region identifiers,but can be otherwise determined.

An event is preferably an intersection of a physical region and a set offeature values. The event can additionally be associated with atimeframe. The event can be predetermined (e.g., a planned event, suchas an awards ceremony), recurring, spontaneous (e.g., a car crash),public, private (e.g., “work,” “at home,” etc.), or any other suitableevent. The event is preferably a spontaneous event that is dynamicallydetermined, but can alternatively be a pre-defined or user-definedevent. A pre-defined or user-defined event is preferably an eventwherein a combination of event parameters defining the event isexplicitly received from or defined by a user, and can be a calendarevent, a recurring event, or any other event defined in any othersuitable manner. A spontaneous event is preferably dynamicallydetermined from the parameters of non-calendar content (e.g.,non-calendar events), wherein the combination of event parametersdefining the event (e.g., event location or region, timeframe,attendees, etc.) is not pre-determined or received from a user(user-defined). The spontaneous event is preferably determined based ona content parameter value, wherein the event can be determined when thecontent parameter value exceeds a threshold value. An event ispreferably determined in response to the probability of the eventexceeding a threshold probability, but can alternatively be determinedin response to any other suitable event. More preferably, the methodfunctions to calculate the probability that an event is currentlyoccurring within a geofence, wherein the geofences and/or event regionsand associated event labels can be ordered based on the respectiveprobability.

The event can additionally be associated with an event timeframe, whichfunctions to delineate the start and stop times of the event. In onevariation, the event timeframe can be used to determine when an eventhas begun, or when the event starts becoming relevant to a population ofusers (e.g., and therefore promoted to users). The event timeframe canalso be used to determine when an event has ended, or when the event hasceased being relevant to a population of users (e.g., and therefore notpromoted to users). However, the event timeframe can be used in anyother suitable manner. The event timeframes can be predetermined ordynamically determined, such as based on the event probability. In onevariation, the event start time can be determined based on the time atwhich an event probability for the geofence rises above a thresholdprobability, and the event end time can be determined based on the timeat which the event probability for the geofence falls below a secondthreshold probability, as shown in FIG. 9. Alternatively, the eventstart time can be determined based on the time at which an eventprobability for the geofence increases beyond a threshold rate, and theevent end time can be determined based on the time at which the eventprobability for the geofence decreases beyond a threshold rate. However,the event timeframe can be otherwise determined.

The set of feature values function to characterize the parameters of thecontent associated with (e.g., geotagged with) a location within thegeofence (geofence content). The set of features for which values aredetermined can be volumetric characteristics, time-dependentcharacteristics, subject matter characteristics, text characteristics,image characteristics, sound characteristics, video characteristics, orany other suitable characteristic. Examples of features include contentvolume within the geofence, content generation density, contentgeneration frequency, patterns of content generation over a period oftime, count of specific subject matter topic mentions, frequency ofmonitored subject matter mentions, changes in the count of monitoredsubject matter mentions, counts of monitored words, changes in counts ofmonitored words, changes in word ratios (e.g., vocabulary size changes),number of monitored sounds, frequency of monitored sound occurrence,changes in counts of monitored sound occurrence, number of monitoredobject images, frequency of monitored object occurrence, changes incounts of monitored object images, authoring persona densities, personaratios, or any other suitable feature descriptive of an event-indicatingaspect of the content. The feature values can additionally include theresults of the event detection and/or features of the event detectionresults, such as the event probability, event probability patterns overa predetermined time period, category probabilities, categoryprobability patterns over a predetermined time period, or include anyother suitable feature value. The combination of features forming theconsidered set of features can be specifically determined for eachgeofence, be determined for a set of geofences, or be determined for anysuitable number of geofences.

The set of features can be learned, selected (e.g., manually orautomatically), computed, or otherwise determined. The set of featurescan be dynamic or substantially static. Each feature type can be acategorization, such as a broad topic or theme (e.g., conflict,violence, fire). The feature types can additionally include subdivisionsof categorizations: classifications (e.g., fire, smoke, ball, 49ers), orany suitable number of subclasses. These feature types can subsequentlybe used to characterize the event. For example, a geofence associatedwith an 80% probability that a sports event is occurring within theencompassed geographic region, a 60% probability that a basketball eventis occurring, and a 20% probability that a football event is occurringcan be tagged with sports, basketball, and football.

The feature values function to represent how closely the content in ageofence is associated with a given feature. The feature values can bepercentages (e.g., content composition, such as the content associatedwith the geofence is 30% sports), numbers (e.g., rated a 5 out of 10 forrecreation, 5 pieces of content associated with recreation, etc.),probabilities (e.g., the content is 50% likely to be about sports), orany other suitable representation of the relationship between thegeofence content and the feature. The feature values are preferablydetermined for each geofence, but can alternatively be determined for aset of geofences.

In a first example of dynamic event detection based on feature values,the probability that an event is currently occurring in a geofence canbe increased in response to detection that the number of peoplegenerating content about a specific category or classification (e.g., aspecific topic) disproportionately increases relative to the change inother categories or classifications. In a second example of dynamicevent detection based on feature values, the probability that an eventis currently occurring in a geofence can be increased in response to theoverall ratio of images of a specific object increasing. In a secondexample of dynamic event detection based on feature values, theprobability that an event is currently occurring in a geofence can beincreased in response to the density of a given type of personaincreasing within the geofence beyond a predetermined threshold, or inresponse to the ratio of a given type of persona relative to the wholeincreasing beyond a threshold ratio.

Receiving content associated with a geofence S100 functions to identifycontent associated with a geofence, wherein the feature values arecalculated based on the content. Receiving content associated with ageofence S100 preferably includes receiving a set of content associatedwith the geofence, wherein the feature values are calculated based onthe plurality of content. However, a single piece of content or anyother suitable volume of content can be received, and the feature valuescan be calculated based on the feature values of individual pieces ofcontent (e.g., instead of the plurality as a whole) or calculated basedon any other suitable content population.

The content is preferably content received from a set of socialnetworking systems, but can alternatively be any other suitable content.The content can be retrieved from the social networking system, receivedin response to the occurrence of a trigger event (e.g., content postingto the social networking system), received in response to a request orquery (e.g., wherein the response or query identifies a user account, ageographic region, a geographic location, or any other suitable searchterm), or otherwise obtained. The content is preferably generated by auser at a user device, and can be posted to or otherwise associated withthe user account on the social networking system. The content can bereceived at a predetermined frequency (e.g., 1 millisecond), in responseto the occurrence of an analysis event (e.g., in response to receipt ofa user request), or at any other suitable frequency.

The content is preferably associated with the geofence in which theassociated content location is located, but can be otherwise associatedwith the geofence. The content can be associated with a geographiclocation (e.g., geotagged) by the social networking system, associatedwith a geographic location by the event detection system (e.g., asdisclosed in Ser. No. 13/678,404 filed 15 Nov. 2012, incorporated hereinin its entirety by this reference), or associated with a geographiclocation in any other suitable manner. Each geofence is preferablyconcurrently monitored, but can alternatively be sequentially monitoredor monitored at any other suitable frequency. In one variation of themethod, the entire habitable surface of a planet can be concurrentlymonitored for content. In a second variation of the method, thelandmasses of a planet can be concurrently monitored for content.However, any suitable geographic location can be concurrently monitoredfor content.

In a first variation of the method, receiving content associated withthe geofence S100 includes monitoring content for a set of geofences.More preferably, the method includes monitoring a set of socialnetworking systems for content associated with one or more of the set ofgeofences. Monitoring content for a set of geofences can include sendingqueries to the set of social networking systems for content associatedwith locations or geographic regions encompassed by each geofence,wherein the content returned in response to the query is associated withthe respective geofence. The queries can be sent at a predeterminedfrequency, or the social networking system can store a standing contentquery for the event detection system. Multiple geofences can beconcurrently monitored, sequentially monitored, or monitored in anyother suitable manner.

In a second variation of the method, receiving content associated withthe geofence S100 includes receiving content from the social networkingsystem (e.g., the content is automatically pushed to the event detectionsystem) and associating the content with a geofence based on therespective content geographic location after content receipt. Thisvariation can additionally include determining (e.g., assigning) ageographic location for the content prior to geofence association. Theevent detection system can receive all content, and discard the contentthat falls outside of the geographic region.

In a third variation of the method, the event detection system retrievesnew content from the set of social networking systems at a predeterminedfrequency (e.g., once every second). The content can be sorted into thegeographic regions according to their associated geographic locations.Content falling within a geographic region can be cached in short-termstorage. Content that is not included in any geographic regions can bediscarded or otherwise stored. However, content can be otherwisereceived and associated with the geofence.

The content is preferably associated with the geofence through a contentidentifier, wherein the content identifier can be stored in associationwith the geofence by the event detection system (e.g., wherein the eventdetection system discards or does not store the media of the content).Alternatively, the content itself (e.g., including the media and anyassociated metadata) can be stored in association with the geofence bythe event detection system. However, the content can be otherwiseassociated with the geofence.

In the variation wherein a content identifier is stored by the eventdetection system, receiving content can additionally include indexingthe content Silo, as shown in FIG. 2. The content is preferably indexedby the event detection system, but can alternatively be indexed by thesocial networking system or by any other suitable computing system. Thecontent can be indexed in response to content receipt, indexed at apredetermined frequency (e.g., wherein multiple pieces of content areconcurrently indexed), indexed in response to event detection, orindexed at any other suitable time.

Indexing the content S110 can include determining a content identifierfor the piece of content S112, which functions to identify the contentwithin the event detection system. Determining a content identifier canadditionally function to determine a retrieval identifier, such that theevent detection system can retrieve or attempt to retrieve the contentfrom the source social networking system based on the contentidentifier. The content identifier can be unique to the event detectionsystem, unique to the social networking system from which the contentwas received, globally unique, generic across social networking systems,or otherwise identified. The content identifier can be determined basedon the content receipt time, content generation time (post time), sourcesocial networking system, associated geofence, authoring user account,substance, or based on any other suitable content parameter.

Indexing the content Silo can additionally or alternatively includedetermining content parameters for the content S114. The contentparameters can include a geographic identifier, timestamp, featurevalues (e.g., the same or different features as that determined for theplurality of content), metadata, substantive parameters, or be any othersuitable content parameter. When the content lacks a geographicidentifier or timestamp, the method preferably determines a geographicidentifier and/or timestamp for the post, using the method disclosed inU.S. application Ser. No. 14/043,479 filed 1 Oct. 2013, incorporatedherein in its entirety by this reference, or using any other suitablemethod. Metadata can include the content source (e.g., the front cameraof a device, back camera of a device, keyboard, touchscreen, etc.), thegeographic identifier (e.g., a geotag), timestamp, authoring useraccount, or any other suitable available metadata. Substantiveparameters can include content type (e.g., image, text, video, audio,etc.), the subject (e.g., nouns, main focus of images, etc.), asdetermined by keyword analysis, natural language processing, imageprocessing, audio processing, or any other suitable processing method,content variables (e.g., number of characters used, number of a specificcharacter used, color intensity, color saturation, color prevalence,audio volume, audio patterns, keyword count, keywords, etc.), or anyother measureable substantive parameter of the content. The contentparameters are preferably determined by the event detection system, butcan alternatively be extracted by the social networking system or by anyother suitable computing system.

Indexing the content can additionally or alternatively include storingthe content identifier and associated content parameters for the contentS116 and discarding the content S118. The content identifier andassociated content parameters can be stored in a content index by theevent detection system or by any other suitable computing system.Alternatively, the content could never be downloaded to the system,wherein the content information (e.g., timestamp, location identifier,post parameter values, etc.) can be determined from the post assupported on the third-party social networking system. However, thecontent can be otherwise indexed. In response to receipt of a queryincluding a location or a time, the content index is preferablysearched, the content identifier associated with geographic identifierssatisfying the query location or timestamps satisfying the query timeidentified, and the content retrieved or requested from the socialnetworking system from which the content was originally received. In onevariation of the method, identifying content associated with a geofencecan include querying the content index for content associated withgeographic locations within the geofence, receiving content identifiersand associated content parameters from the content index, and performingthe event detection analysis on the returned information. The contentindex query can additionally include a timeframe, other time limit, orany other suitable query value. However, the content index can beotherwise used.

Receiving content associated with a geofence S100 can additionallyinclude determining a set of content for event detection analysis S120,which functions to reduce the amount of content processed during theanalysis. The set of content is preferably a plurality of content, butcan alternatively be a single piece of content or include any othersuitable number of content. The set of content can be limited temporally(e.g., based on temporal proximity), by subject matter (e.g., whereinall the content associated with the geofence is filtered forevent-related content, such that the feature values are determined basedon event-related content only), or restricted by any other suitableparameter.

In a first variation, determining the plurality of content for analysisS120 includes identifying content, associated with the geofence, whichwas generated within an inclusion time threshold of a reference time.The reference time can be an instantaneous time, the posting orgeneration time of a piece of content associated with the geofence(e.g., the last piece of content that was generated), the receipt timeof a piece of content (e.g., the last piece of content that wasreceived), or be any other suitable reference time. The inclusion timethreshold can be predetermined or dynamically determined. The inclusiontime threshold can be constant or change as a function of time, featurevalue (e.g., frequency, density, etc.), event probability, or change inany other suitable manner. In a second variation, any content associatedwith the geofence within an inclusion time threshold from theinstantaneous time can be included within the plurality. In a thirdvariation, any content associated with the geofence is included in theplurality as long as an event is detected. In a fourth variation, onlynew content (e.g., content received since the last content pluralitydetermination or event analysis) is included in the plurality. In afifth variation, only content related to the event is included in theplurality. However, the plurality of content can be otherwise determinedfor analysis. Content pluralities for different geofences are preferablydetermined in the same manner, but can alternatively be determined usingdifferent methods.

In a specific variation of the first variation, a first piece of contentis included in the plurality of content when the first piece of contentis associated with a timestamp that was within the inclusion timethreshold of a piece of content of the plurality, such that the contentwithin the plurality are associated by temporal proximity. In a specificexample, a first piece of content, generated at a first timestamp, canbe part of the plurality. A second piece of content, generated at asecond timestamp, can be included in the plurality when the secondtimestamp is within the inclusion time threshold of the first timestamp(e.g., before or after). Alternatively, the second piece of content canbe excluded from the plurality when the second timestamp is outside ofthe inclusion time threshold of the first timestamp.

In a second specific variation of the first variation, determining theplurality of content for analysis includes, in response to receipt ofthe new content, identifying a set of content associated with thegeofence, wherein the latest piece of content within the set wasgenerated within the inclusion time threshold from the new content, suchthat each piece of content within the set was generated within theinclusion time threshold from the next piece of content. If the set isempty, the new piece of content is added to the empty set. The contentwithin the set are discarded if no new pieces of content are added tothe set within the predetermined period of time. The content is retainedwithin the set if new pieces of content are added to the set within thepredetermined period of time. The inclusion time threshold can remainconstant, vary as a function of the number of content (e.g., increase ordecrease with increased content in the set), vary as a function offrequency (e.g., increase or decrease with increased content generationfrequency), or vary in any other suitable manner. However, the pluralityof content can be determined in any other suitable manner.

Determining a set of feature values for each of the set of geofencesS200 functions to reduce the content associated with each geofence intoa set of metrics that can be used to analyze the social activity in thegeofence. The feature values can be determined based on the plurality ofcontent (e.g., content associated by inter-set temporal proximity,etc.), determined based on individual feature values for each piece ofcontent from the plurality of content, determined based on the newcontent received since the last time the feature values were determinedfor the geofence, determined based on content generated, received, orotherwise associated with a time within a predetermined time period ofthe value determination time, determined based on content associatedwith a single or set of times, determined based on all contentassociated with the geofence, or determined based on any other suitablecontent.

The feature values are preferably determined based on the plurality ofcontent as a whole or as a population, as shown in FIG. 4, but canalternatively be determined on a per-content or individual contentbasis, as shown in FIG. 5. For example, a keyword ratio can bedetermined based on the occurrence of a set of keywords within theentire population of the content plurality (e.g., feature determinationbased on the content plurality as a whole), or be determined from theindividual ratios for the set of keywords within each piece of contentof the plurality (e.g., feature determination based on individual piecesof content within the plurality).

Determining a set of feature values for each geofence S200 can includedetermining the feature values for each of a plurality of features.Alternatively, determining the set of feature values can includedetermining a reduced set of features from the plurality of features,then determining the feature values for each of the features in thereduced set. However, any other suitable set of feature values can bedetermined. The feature values can be determined at a predeterminedfrequency, in response to receipt of new content associated with thegeofence, in response to event detection or determination of an on-goingevent within the geofence, or in response to receipt of a query (e.g.,an event query or geofence query), or determined at any other suitabletime. The feature values can be calculated, determined based on a graph,selected from a chart, empirically determined, output from any module,determined using a set of machine learning algorithms, or otherwisedetermined.

Determining the feature values S200 can include determining thepopularity of the event S220, which can be used to detect an event,categorize the event, or used to post-process the event information inany other suitable manner. The event popularity can additionallyfunction as a filter for certain applications (uses) of the eventdetection. The event popularity can be determined based on the localpopularity of the event, the global popularity of the event, and/or thespread of the event, as shown in FIG. 15. However, the event popularitycan be determined based on change parameters of any of theaforementioned features (e.g., the rate of change or the acceleration ofchange), combination of the three, or be determined based on anycombination of any other suitable feature. The event popularity can bedetermined based on the plurality of content associated with thegeofence, any content associated with the geofence, content unassociatedwith the geofence, such as content associated with a secondary geofencedifferent from the first or content unassociated with any geofences orgeographic locations, content associated with the event (e.g., contentassociated with the event based on keywords, references to users knownto be associated with the event, sentiment, tags, or any other suitablereference to the event), or based on any other suitable content. Thecontent unassociated with the geofence (outside content) can bedetermined to be about the event when the outside content sharesattributes with the event content (e.g., timeframe, subject matter,combination of keywords, combination of topics, shared media, directreferences, etc.), or be determined in any other suitable manner. Theevent popularity, local popularity, global popularity, and/or spread canadditionally be determined based on the feature values, eventprobabilities, and/or any other suitable parameter associated withsecondary geofences. The event popularity, local popularity, globalpopularity, and/or spread can additionally be determined based on thegeographic location of content viewers (e.g., users, user accounts, oruser devices that view or otherwise access the content), as determinedfrom social network APIs, content references, or determined in any othersuitable manner.

The local popularity is preferably measured as the popularity of theevent (e.g., popularity of the subject matter, topic, etc.) within thegeofence and/or proximal geofences, but can be alternatively determined.In a specific example, the local popularity can be determined based onthe density of content referencing a common subject or topic within thegeofence within a predetermined period of time. In another example, thelocal popularity can be determined based on the frequency of contentreferencing a common subject or topic within the geofence. The eventpopularity preferably scales with local popularity, but canalternatively be weighted by local popularity, or otherwise influencedby local popularity.

The global popularity is preferably measured as the popularity of theevent in geofences outside of the event geofence, but can bealternatively determined. The global popularity is preferably determinedbased on content generated or received within a threshold period of timefrom event detection in the primary geofence (e.g., before or after),but can alternatively be determined based on content generated orreceived concurrently with the primary geofence content underlying theevent detection, or determined based on any other suitable set ofcontent. In one variation, the global popularity can be the number ofuser accounts or users generating content about the event outside of theevent geofence. In a second variation, the global popularity can be thevolume of content generated about the event outside the geofence. In athird variation, determining global popularity can include determiningsecondary geofences associated with the event, wherein the secondarygeofence is different from the first geofence. The secondary geofence ispreferably associated with the event through content associated with thesecondary geofence. In a first example, the secondary geofence caninclude one or more pieces of content associated with the event. In asecond example, a secondary event can be detected within the secondarygeofence, wherein the secondary event can be associated with the eventdetected within the primary geofence. The content or secondary event canbe associated with the event by having a content or feature matchparameter higher than a match threshold with the event, event-associatedcontent, or content of the primary geofence. The content or secondaryevent can be associated with the event when the underlying contentreferences one or more of the plurality of content associated with theprimary geofence, references the event, references the geofence, orreferences any other suitable parameter related to the event. However,the secondary geofence can be associated with the event in any othersuitable manner. The event popularity preferably scales with globalpopularity, but can alternatively be weighted by local popularity, orotherwise influenced by local popularity.

The spread is preferably determined as a function of the geographicdistance between the event geofence and a secondary geofence associatedwith the event-related content, but can be alternatively determined.More preferably, the spread is determined (e.g., measured) as a functionof the geographic distance between the event geofence and a set ofsecondary geofences associated with event-related content (e.g., allsecondary geofences associated with event-related content), but canalternatively be determined based on any other suitable set ofgeofences. However, the spread can be otherwise determined. In oneexample, the spread can be determined based on the distances between theevent geofence and the secondary geofences. In a second example, thespread can be determined based on the distance between the eventgeofence and the furthest secondary geofence. In a third example, thespread can be based on the distance between the event and the furthestsecondary geofence satisfying a content parameter threshold (e.g.,event-referencing content density or frequency of generation). In afourth example, the spread can be based on the velocity and/oracceleration at which event-related content is propagating throughsecondary geofences. In a fifth example, the spread can be based on thedistribution of secondary geofences, wherein a large spread can bedetermined in response to a wide distribution of secondary geofencelocations, and a small spread can be determined in response to a narrowdistribution of secondary geofence locations. However, the spread can beotherwise determined. The spread can be determined for the generalpopulation, a specific persona, or any other suitable set of users orgeofences sharing a common attribute. The spread can be calculated basedon the distances between the primary geofence and the secondarygeofence, selected as the furthest distance between the primary geofenceand a secondary geofence, or determined in any other suitable manner.The event popularity preferably scales with spread, but canalternatively be weighted by local popularity, or otherwise influencedby local popularity.

Determining the event popularity S220 can additionally or alternativelyinclude predicting event popularity, which can function to determinewhether an event will be popular (e.g., discussed globally) before therespective event popularity exceeds the popularity threshold. The eventpopularity can be predicted before the initiation of planned events,immediately following the occurrence or detection of an unplanned event,or predicted at any other suitable time relative to the event. Eventspredicted to be popular can be promoted within a list of possibleon-going events. Predicting event popularity can include predicting thepopularity based on the event probability, wherein a specific eventprobability or pattern of event probability over a time period withinthe geofence can be correlated with a popularity probability orpopularity score. The correlation between event probability and eventpopularity is preferably learned (e.g., using machine learningtechniques), but can be otherwise determined. Alternatively oradditionally, predicting event popularity can include predicting thepopularity based on the combination of labels or categories associatedwith the event. However, the event popularity can be otherwisepredicted.

Determining the event popularity S220 can additionally or alternativelyinclude determining the event nexus, which can be used to establish theprimary geofence or set of geofences. The event nexus is preferably thegeographic location or region in which the event occurred, but canalternatively be any other suitable geographic region. In one variation,the event nexus (primary geofence) is the geofence in which the eventwas first detected (e.g., in which the event was detected at theearliest timestamp). In a second variation, the event nexus can bedetermined based on the distribution of geofences in which the event isdetected, wherein the geofences can be clustered about or in relation tothe event nexus. In a third variation, the event nexus can be determinedbased on event-associated metadata (e.g., compass headings). Forexample, the direction of the camera can be extracted fromevent-associated images (e.g., based on the compass heading) and used totriangulate the event nexus. In a fourth variation, the event nexus canbe the geofence having the highest event probability for the event.However, the event nexus can be otherwise determined.

Determining an event probability for the respective geofence based onthe set of feature values S300 functions to determine whether an eventwas occurring at the time of geofence content generation. The eventprobability is preferably determined by an event determination modulethat receives a set of feature values and calculates the eventprobability based on the set of feature values. However, the eventprobability can be determined by any other suitable system. Determiningthe event probability can include selecting a reduced feature set(feature subset) from the full set of features (plurality of features)for the respective geofence and determining the event probability fromthe values of the features in the reduced feature set. However, theevent probability can be determined based on the full set of features orotherwise determined. The event probability for the geofence canadditionally or alternatively be determined based on the feature values,event probabilities, category probabilities, and/or any other suitableparameter of proximal or adjacent geofences, geofences within a sharedtimezone, or any other suitable geofence.

Selecting the reduced feature set (feature subset) functions to reducethe number of feature values processed by the event determination moduleto decrease computation time and/or increase resource utilizationefficiency. The reduced set of features preferably includes less thanthe full set of features, but can alternatively be the entire pluralityor be any other suitable set of features. The reduced set of features ispreferably part of the plurality of features, but can alternatively beany other suitable set of features. In one example, the reduced featureset includes a set of elements, wherein each element is a superclass ofa subset of the feature plurality (e.g., the reduced feature setincludes a set of parent nodes of a hierarchy tree, wherein the featureplurality subsets are child nodes of the parent nodes). However, thereduced feature set can include any other suitable features. In oneexample, selecting the reduced feature set includes reducing a pluralityof 30,000 features to a set of 4,000 features. The reduced feature setis preferably determined by applying machine learning techniques, butcan alternatively be determined in any other suitable manner. Machinelearning techniques that can be applied include supervised learning,clustering, dimensionality reduction, structured prediction, anomalydetection, and neural nets, but can alternatively include any othersuitable technique. Examples of supervised learning techniques includedecision trees, ensembles (bagging, boosting, random forest), k-NN,Linear regression, naive Bayes, neural networks, logistic regression,perceptron, support vector machine (SVM), and relevance vector machine(RVM). Examples of clustering include BIRCH, hierarchical, k-means,expectation-maximization (EM), DBSCAN, OPTICS, and mean-shift. Examplesof dimensionality reduction include factor analysis, CCA, ICA, LDA, NMF,PCA, and t-SNE. An example of structured prediction includes graphicalmodels (Bayes net, CRF, HMM). An example of anomaly detection includesk-NN Local outlier factor. Examples of neural nets include autoencoder,deep learning, multilayer perceptron, RNN, Restricted Boltzmann machine,SOM, and convolutional neural network. However, any other suitablemachine learning technique can be used. The machine learning techniquesand/or models used to select the reduced feature set can besubstantially static or dynamically change over time.

Determining the event probability based on the feature values of thefeatures in the reduced set functions to determine the probability of anevent within the geofence based on the geofence content. The eventprobability can be the probability that an event is occurring within thegeofence, the probability that an event of a given type is occurringwithin the geofence (e.g., a set of probabilities corresponding to a setof event types or categories), or be a probability of any other suitableevent parameter. The event probability can be calculated from thefeature values (e.g., from weighted feature values), selected from achart or graph based on the feature values, selected based on thespecific combination of feature values, output from any module (e.g.,machine learning module), or otherwise determined. In one variation, themodule (e.g., machine learning methods) used to determine the eventprobability can be static or dynamic (e.g., can change over time, basedon content parameters, prediction accuracy or precision, etc., change inresponse to the occurrence of a trigger event, or change in any othersuitable manner). In one variation of the method, a common eventprobability module used for all geofences within a set of geofences(e.g., the same model is used for all geofences). In a second variationof the method, each geofence is associated with a different eventprobability module. However, the event probability modules can beassociated with geofences in any other suitable manner. The eventprobability modules of multiple geofences can dynamically varyindependently, vary as a population of modules, or vary in any othersuitable manner. The event probability modules can vary as a function ofindividual or global content parameters, prediction accuracy orprecision, types of enclosed venues, or vary in any other suitablemanner. In one example, a first event probability module (e.g., firstset of machine learning models) is associated with a first geofence whenthe enclosed venue is categorized as a mall, and a second eventprobability module (e.g., a second set of machine learning models,different from the first) is associated with the first geofence when themall is converted into a church. However, the event probability modulescan be determined for a set or an individual geofence in any othersuitable manner.

The event probabilities can additionally or alternatively includeaccounting for typical (e.g., baseline) content volume, subject matter,author personas, or other content parameters for the geofence S320. Thetypical content parameters are preferably baseline feature values, butcan alternatively be any other suitable content parameter associatedwith the geofence. The typical content parameters are preferablypatterns, but can alternatively be averages, minima, matrices, points ina hyper-dimensional space, density surfaces, or any other suitablevalue. The typical content parameters can be learned using machinelearning techniques, calculated, received from a user, and/or otherwisedetermined. The typical content parameters are preferably used tonormalize the determined feature values. Baseline feature values can bedetermined for all features or a subset of features.

In a first example, the content volume in New York's Times Square istypically higher than the content volume on a freeway, wherein an eventwould not be determined for the Times Square geofence but would bedetected for the freeway, given the same absolute volume change. In asecond example, a predetermined set of keywords or topics can beassociated with Times Square as typical keywords (e.g., “Times Square,”“NYC”) and a second set of keywords or topics can be associated with thefreeway (e.g., “traffic,” “cars”), wherein an event is not detected inresponse to an increase in the number of keywords in thegeofence-associated set, but is detected in response to an increase inthe number or ratio of keywords outside of the geofence-associated set.For example, an event can be detected in response to the keyword “cars”increasing in number or ratio in the Times Square geofence content, asshown in FIG. 11. In a third example, a typical pattern of contentgeneration frequency or volume can be determined for an airport, asshown in FIG. 10. In a specific example, the volume of content typicallyincreases after a plane has landed due to passengers posting contentafter the communication hiatus in the air. While this can be consideredan event, this arrival event is typically not interesting or relevant tomost users. Therefore, the pattern of content volume increase afterairplane arrival can be learned, and subsequently determined featurevalues can be discounted based on the learned pattern to distinguish thepattern from a typical airport event and an airport event of interest.Alternatively or additionally, the pattern of content volume can beassociated with a specific schedule (e.g., a learned airline landingschedule), or determined independent of a specific time, such that thepattern can be applied to the airport content based on an externalairline schedule (e.g., wherein the scheduled or adjusted landing timecan be determined and the pattern applied after schedule determination).However, the typical content parameters can be otherwise applied.

The method can additionally include detecting an event within thegeofence in response to the event probability exceeding a thresholdevent probability S400, as shown in FIGS. 1 and 9. The threshold eventprobability can be the same for all geofences, different for eachgeofence, different for different sets of geofences, or vary in anyother suitable manner. The different sets of geofences can be definedbased on shared characteristics, such as content generation patterns,event probability patterns, enclosed venues (e.g., whether the geofenceencloses a ballpark, stadium, or music venue), or based on any othersuitable characteristic. The threshold event probability can besubstantially constant over time, vary as a function of feature value orcontent parameters, or vary in any other suitable manner.

The method can additionally include determining the threshold eventprobability. The threshold event probability can be determined for thegeofence, be determined for a set of geofences, or be determined for allthe geofences. The threshold event probability can be received from auser, automatically determined (e.g., using a set of machine learningalgorithms, such as MLAs wherein user-determined events are used as thegroundtruth), dynamically determined, or otherwise determined. Thethreshold event probability can be determined based on historical eventprobabilities associated with the respective geofence, respective set ofgeofences, or a training set of geofences, determined based onhistorical feature values associated with the respective geofence,respective set of geofences, or a training set of geofences, ordetermined based on any other suitable information.

The method can additionally include determining a second eventprobability for the geofence, which can function to continually monitorthe event probability within geofence. The second event probability ispreferably determined for geofences with detected, on-going events, butcan alternatively be determined for any other suitable geofence. Thesecond event probability is preferably determined in response to theoccurrence or detection of a trigger event, but can alternatively bedetermined at any other suitable time. The trigger event can be thereceipt of new content associated with the geofence from a socialnetworking system, the satisfaction of a time duration (e.g., whereinthe probability is calculated at a predetermined frequency), in responseto a request from a user, or be any other suitable trigger event. Thesecond event probability is preferably determined in substantially thesame manner as initial event probability determination, but canalternatively be determined in any other suitable manner. The secondevent probability can be determined based on the plurality of contentassociated with the geofence (e.g., the entire plurality, including oldand newly received content), new content received since the prior eventprobability determination, or be determined based on any other suitableset of content. The second event probability can be determined usingsubstantially the same reduced feature set and event probabilitythreshold as initial event probability determination, but canalternatively be determined using a different reduced feature set and/orevent probability threshold. Each event probability determination afterthe initial event probability determination can use the same feature setor a different feature set, and/or the same event probability thresholdor different event probability threshold. However, the second eventprobability can be determined in any other suitable manner.

The method can additionally include characterizing the event S500, whichfunctions to give a user an indication of the type of event occurringwithin the geofence, as shown in FIG. 7. Characterizing the event caninclude presenting, naming, or otherwise associating the event with oneor more event identifiers. The event identifiers can be determined fromthe features having the highest probabilities, percentages, or othervalue for the content, but can alternatively be keywords, phrases,images, videos, sounds, or other media extracted from the content. Inone example, the label can include a non-generic noun most frequentlymentioned in the content. However, the label can be derived andassociated with the event in any other suitable manner.

The method can additionally include post-processing the feature values,as shown in FIG. 8, which functions to refine the labels associated witheach event (e.g., refine event characterization, examples shown in FIGS.13 and 14). Post-processing the feature values preferably does so byresolving redundancies (e.g., wherein a super-class and a sub-class areboth included in the characterization), resolving conflicts (e.g.,wherein two unrelated or conflicting labels are associated with theevent when characterizing the event), replacing the labels with moredescriptive labels, or refining the labels in any other suitable manner.A post-processing module preferably post-processes the feature values,any other suitable module can post-process the feature values.Post-processing the features can be desirable because not all featuresare considered in event determination (e.g., due to the computationallyintense requirements needed to process the plurality of the features).

Post-processing the feature values preferably includes receiving theoutput of the event detection module, identifying secondary features foranalysis based on the output, and refining the labels based on thevalues of the secondary features. However, the feature values can beotherwise post-processed.

The output of the event detection module preferably includes theprobability that an event was occurring at the time the content wasgenerated or posted, the labels associated with the event, and thepercentages or probabilities for each label, but can additionally oralternatively include any other suitable information. The combination ofthe event probability, labels, and/or label probabilities preferablyform a signature pattern that the post-processing module recognizes orassociates with another known signature pattern, wherein thepost-processing module can select a second set of features (secondaryfeatures) from the plurality of features based on the signature pattern.Alternatively, the post-processing module can determine whichcombinations of labels are likely or unlikely, and refine the labelstoward likely label combinations.

The second set of features is preferably different from the first set offeatures used to determine the event probability, more preferablyentirely different but alternatively including at least one featuredifferent from the first set. The second set of features can be a subsetof the plurality of features, the entirety of the plurality of features,or any other suitable set of features. The second set of features ispreferably learned (e.g., applying machine learning techniques), but canalternatively be received from a user, empirically determined, orotherwise determined.

Post-processing the feature values can additionally include categorizingthe event S520, which can function to identify whether the event will berelevant to a specific entity. In this variation, the post-processingmodule can select a second set of features that are targeted towarddetermining whether the event falls within a category (e.g., whether theevent will be relevant to the entity). As above, the second set offeatures can be selected based on the event probability, labels, or anyother suitable information. The post-processing module can additionallyor alternatively select a subset of features from the second set foranalysis, based on the output of a prior module (e.g., the eventdetection module, second post-processing module, etc.). Alternatively,the post-processing module can be specific to a category, wherein thesecond set of features are predetermined for the respective category andcooperatively determine whether the event falls within the respectivecategory. The second set of features can be learned (e.g., throughmachine learning techniques), received from a user, or otherwisedetermined.

The second set of features is preferably associated with a single eventcategory, wherein the features of the second set are cooperatively usedto determine the probability of whether an event can be categorized asthe respective event category. Alternatively, the second set of featurescan be associated with multiple event categories, wherein the featuresof the second set are cooperatively used to determine whether an eventshould be categorized as a first event category or as a second eventcategory (e.g., wherein events having a first probability can becategorized as the first event category, and events having a secondprobability can be categorized as the second event category). However,the second set of features can be otherwise used.

For example, the post-processing module can select a first, second, andthird feature for value analysis in response to determination of a firstcombination or pattern of event probability and label probability, andcan select a fourth, fifth, and sixth feature for value analysis inresponse to a determination of a second combination or pattern of eventprobability and label probability. The post-processing module canadditionally consider (e.g., extract feature values for) content that isnot explicitly associated with the geographic location (non-geographiccontent), wherein the non-geographic content set can be associated withthe event based on keywords, references to users known to be associatedwith the event, sentiment, tags, or any other suitable reference to theevent. In one example, the post-processing module can determine whetherthe event would be of interest to a news facility, wherein the secondset of features can include features that best identify news events(e.g., as opposed to recurring events, local events, scheduled events,etc.). For example, the second set of features can include featuresindicative of the popularity of the event or topic, virality features,spontaneity features, or any other suitable features.

The method can additionally include determining the second subset offeatures. The second subset of features can be determined for each of aplurality of event categories (e.g., wherein each event category isassociated with a second subset of features), can be determined for aplurality of event categories (e.g., wherein multiple event categoriesare associated with a common second subset of features), or can bedetermined for any other suitable set of event categories. The secondsubset of features can be selected for the event category by a set ofmachine learning algorithms, by a user, or determined for the eventcategory in any other suitable manner.

The category probability is preferably determined by a set of machinelearning algorithms based on the second set of feature values (e.g., thesame set of machine learning algorithms that determined the second setof features or a different set of machine learning algorithms), but canalternatively be calculated based on the feature values for therespective features of the second subset, be selected from a graph orchart, or be determined in any other suitable manner. In one variation,the category probability can be calculated from an equation (formula),wherein the equation can be determined by a set of machine learningalgorithms. The set of machine learning algorithms determining theequation can be the same set of machine learning algorithms used todetermine the second subset of features, but can alternatively be adifferent set of machine learning algorithms (second set of machinelearning algorithms), or be any other suitable set of machine learningalgorithms.

The event can be categorized with the category in response to thecategory probability exceeding a category probability threshold. Thecategory probability threshold can be predetermined (e.g., received froma user), automatically determined (e.g., using machine learningtechniques), dynamically determined (e.g., based on frequency of eventcategorization with the category, etc.), or otherwise determined.However, the event can be categorized in any other suitable manner. Theset of machine learning algorithms determining the equation can be thesame set of machine learning algorithms used to determine the secondsubset of features or determine the category probability, but canalternatively be a different set of machine learning algorithms (e.g.,third set of machine learning algorithms), or be any other suitable setof machine learning algorithms.

Multiple category probabilities can be determined for an event. Thecategories associated with the event can be substantially static or varyas a function of time, feature value, or any other suitable parameter.For example, an event can be initially categorized as a local event, andrecategorized or additionally categorized as a national event when theacceleration of global popularity and/or spread exceeds a thresholdacceleration. Each event can be associated with a single category,multiple categories, or any suitable number of categories. When theevent can only be associated with a single category, the category havingthe highest category probability is preferably associated with theevent. However, any other suitable category can be associated with theevent.

The method can additionally include determining the geographic extent ofthe event S600, which functions to determine the geographic regioncorresponding to the event. Determining the geographic extent of theevent can additionally or alternatively function to provide a differentset of content (e.g., second content plurality) that can be used todetermine the feature values. Determining the geographic extent of theevent can be particularly useful if the method monitors multiplenon-overlapping geofences instead of monitoring multiple overlappinggeofences. Determining the geographic extent of the event S600 caninclude detecting events within a first and second geofence S620,determining that the events are a common event S640, and determining athird geofence enclosing the first and second geofences in response todetermination that the events are a common event S660. However, thegeographic extent can be determined in any other suitable manner.

The events within the first and second geofence are preferably detectedin the manner discussed above, but can alternatively be determined inany other suitable manner. In one variation, a first event is detectedin the first geofence based on values for a first set of features, whilethe second event is detected in the second geofence based on values fora second set of features different from the first set, wherein thefeature sets associated with the first and second geofences can bedetermined based on historical events and/or feature values associatedwith the respective geofence. In a second variation, the first andsecond events can be detected in the first and second geofences based onvalues of the same set of features. However, the events can be otherwisedetected. The first and second geofences preferably representgeographically adjacent geographic regions, but can alternativelyrepresent geographically distant geographic regions. Geographicallyadjacent geographic regions can be contiguous regions (e.g., wherein thefirst and second geofences share a border), cornerwise regions (e.g.,cornerwise geofences), geographic regions within a predeterminedgeographic distance, geofences within a predetermined number ofgeofences apart, geographic regions on a contiguous land mass, or beotherwise geographically adjacent. Geographically distant geographicregions can be separated by a predetermined geographic distance (e.g.,by a predetermined number of geofences), by a physical barrier (e.g., awall, such as the Great Wall of China, a water body, etc.), or beotherwise geographically distant. The events can be concurrentlydetected in the first and second geofence, be detected within apredetermined time of each other (e.g., received from a user, learned,etc.), such as within 30 minutes of each other, or be related temporallyin any other suitable manner.

Determining that the first event and the second event are a common eventS640 functions to determine whether the third geofence should bedetermined. A common event determination module of the event detectionsystem preferably determines whether the first and second events are acommon event, but any other suitable system can alternatively make thedetermination. The first and second events are preferably a common eventwhen the events are the same event (e.g., the same baseball game isoccurring in both geofences), but can alternatively be common eventswhen the events are related, or be considered common events based on anyother shared feature. The first and second geofences are preferably bothevent nexus, but can alternatively be any other suitable geofence.

In a first variation, the first and second events can be common eventswhen all or a subset of the feature values substantially match (e.g.,are within a predetermined threshold difference of each other). Forexample, the first and second events can be considered common eventswhen they are substantially concurrently detected, include substantiallysimilar subject matter, have substantially similar content postfrequencies, have substantially similar labels, or share any othersuitable feature value.

In a second variation, the first and second events can be common eventswhen the content has substantially the same parameters (e.g., contentinformation) and/or are originally generated (e.g., unique compared tothe rest of the content plurality or the content of other geofences).For example, events occurring at a first and second geofence can beconsidered a common event when both geofences are associated withoriginally generated videos or images sharing common subject matter(e.g., a concert), while a third event detected in a third geofence isnot considered a common event with the first and second events when thethird event was primarily detected based on copied content (e.g.,reposts, references, etc.).

In a third variation, the first and second events can be considered acommon event when the respective first and second geofence have apredetermined association. For example, the first and second geofencecan represent geographic regions located within a common venue (e.g.,stadium), or be associated with a common venue (e.g., represent astadium and a parking lot for the stadium, respectively).

In a fourth variation, whether the first and second events are a commonevent can be determined using machine learning techniques to determine aprobability of event commonality, wherein the events can be considered acommon event in response to the commonality probability exceeding athreshold probability. However, whether the first and second events area common event can be otherwise determined.

Determining a third geofence enclosing the first and second geofencesS660 functions to determine the geographic region associated with theevent. The third geofence is preferably subsequently stored inassociation with the event. Alternatively, the event can be stored inassociation with the third geofence, stored in association with theconstituent geofences within the third geofence, or the association canbe stored in any other suitable manner. The third geofence preferablyencloses the entirety of the first and second geofences, but canalternatively enclose a portion of the first and second geofences.Determining the third geofence can additionally function to determinewhich geographic identifier (e.g., which level of geographicabstraction) should be associated with the event. The third geofence ispreferably determined in response to determination that the first eventand the second event are a common event, but can alternatively bedetermined at any other time.

In a first variation, the third geofence can be determined in the mannerdisclosed in Ser. No. 14/501,436, filed 30 Sep. 2014 and incorporatedherein in its entirety by this reference.

In a second variation, the third geofence can be determined based ongeofence event probabilities, wherein the third geofence can enclosegeofences having event probabilities above a threshold event probability(e.g., the same as or different from that used to determine whether anevent was occurring in the respective geofence). In a specific example,the boundaries or anchor points of the third geofence can be determinedbased on the geofence boundaries separating geofences having eventprobabilities above the threshold event probability and geofences havingevent probabilities below the threshold event probability.

In a third variation, the third geofence can be determined based on therespective feature values of the encompassed geofences, such as contentposting frequency, wherein the third geofence borders can be determinedin substantially the same manner as the second variation. The featurevalues can be feature values generated from the content plurality, fromhistorical content (e.g., content outside of the content pluralityand/or unassociated with the event), or from any other suitable set ofcontent.

In a fourth variation, the third geofence can be determined based on theresultant plurality of content within the third geofence. In particular,the third geofence can be determined based on the event probability forthe third geofence (third event probability), wherein the third eventprobability can be determined based on the plurality of contentassociated with the third geofence. The third geofence is preferablydetermined when the associated event probability exceeds a thresholdevent probability (e.g., the same as or different from that used todetermine whether an event was occurring in the respective geofence),but can be determined in any other suitable manner. In this variation,the third geofence can be recursively determined wherein the boundariescan be selected, the associated content plurality determined, the eventprobability calculated, and new boundaries selected in response to theevent probability falling below the event probability threshold.However, the third geofence can be otherwise determined.

Determining the geographic extent of the event Shoo can additionallyinclude determining a geographic identifier for the third geofence, suchthat the geographic identifier can be associated with the common event.The geographic identifier can be determined in response to determinationof the third geofence or be determined at any other suitable time. Thegeographic identifier can be a venue included in a threshold proportionof the constituent geofences, a political region included within thethird geofence, a political region mostly covered by the third geofence(e.g., wherein the third geofence covers at least a threshold proportionof the political region), a venue name extracted from the content of theplurality, a keyword extracted from the content, or be any othersuitable identifier identified in any other suitable manner.

The method can additionally include detecting the end of an event. Theend of the event can be detected when the event probability (e.g.,second event probability) falls below an event probability threshold(e.g., the same as or different event probability threshold from thatused to determine whether an event was occurring in the respectivegeofence), when a feature value pattern is detected, when a featurevalue surpasses a predetermined value threshold, or be determined in anyother suitable manner.

The method can additionally or alternatively include differentiatingbetween the end of an event and a dip in the generated content, whichcan additionally function to bridge the dip in event probability duringan intermission in the event. In this variation, featuresdifferentiating event endings and event intermissions can be analyzed inresponse to detection of an event dip. The probability can beartificially maintained at the threshold probability in response tocategorization that the event is in an intermission and has not ended.In one example, an event end can be detected in response to a ratio ofscores being posted relative to the entirety of the subject matterincreasing prior to the dip, while an event intermission can be detectedin response to the ratio scores relative to the entirety of the subjectmatter remaining within a threshold percentage of a secondary subjectmatter ratio.

The method can additionally include artificially maintaining an eventprobability above a threshold level S700, which functions to preventprobability dips in an event from registering as two events in thesystem when the event probability is used to determine the beginning andending timestamps of the event. This can be particularly useful forscheduled events in which there is an intermission or halftime when usercontent generation about the event tends to drop (e.g., due to the usershifting focus to other subject matter, shifting to anon-content-generating register such as going to get food, etc.). Theevent probability is preferably artificially maintained at or above athreshold level for certain types of events, such as scheduled events(e.g., wherein the event is verified by external schedule) or eventsfalling within a predetermined set of categories, but can alternativelybe applied to any type of event. The event probability dip is preferablystill detected, but is artificially filled in for event presentationpurposes (e.g., listing purposes), as shown in FIG. 18. Artificiallymaintaining an event probability above a threshold level preferablyincludes artificially holding the event probability at a thresholdprobability for a threshold period of time after a potential event endis detected (e.g., after a probability dip), but can be alternativelymaintained. The threshold probability is preferably selected to promotethe event within an on-going event listing (e.g., as shown in FIG. 7),but can be determined in any other suitable manner. The threshold timecan be determined based on the maximum content volume for the eventwithin the geofence, average content volume for the event within thegeofence during a predetermined time period prior to probability dip,typical dip duration for the event type, type of event, types of personaat the event, types of persona typically within the geofence, or anyother suitable feature. In one example, in response to the event beingcategorized as a soccer game, the threshold time period can besubstantially equal to or longer than the halftime duration. The numberof times the event probability is artificially maintained canadditionally or alternatively be limited, wherein the number of timesthe event probability is artificially maintained can be selected basedon one or more of the features discussed above, or based on any suitablefeature. In one example, in response to the event being categorized as asoccer game, the event probability can be artificially maintained onceduring the event to accommodate for the halftime. In a second example,in response to the event being categorized as a football game, the eventprobability can be artificially maintained 6 times to accommodate fortime-outs. However, the number of times the probability can beartificially maintained can be unlimited or otherwise restricted.However, the event probability can be otherwise artificially adjusted.

The method can additionally include weighting the event probability foruser presentation. When a list of probable events is presented to auser, the event probabilities tend to fall along a continuum. Even whenthe events are arranged in decreasing order based on the respectiveprobabilities, it is difficult for a user viewing the list todistinguish between the events of importance and the events that areunimportant. In other words, because the event probabilities fall alonga continuum, the user does not know what the cutoff probability shouldbe. In one variation of the method, the event probabilities can beselectively weighted, wherein events having a probability above athreshold probability can be unweighted or positively weighted (e.g.,with a weight of 1 or more), and events having a probability below athreshold probability can be negatively weighted (e.g., with a weightbelow 1). The threshold probability is preferably 0.5 (50%), but canalternatively be any other suitable threshold probability. In anothervariation of the method, probabilities for events having certaincategorizations (e.g., conflict, fight) can be promoted (e.g., for asecurity monitoring application), while probabilities for events havingother categorizations (e.g., “party”) can be discounted. However, theevent probability can be adjusted in any other suitable manner.

The method can additionally include sending a content feed for the eventto a remote user device S800. Sending the content feed can includeselecting content for inclusion in the content feed S820, aggregatingthe selected content into a content feed S840, and sending the contentfeed to the remote user device S860. The content feed can be sent inresponse to receipt of a request for the content feed associated withthe event, in response to receipt of an event selection, or in responseto any other suitable sending event.

Selecting content for inclusion in the content feed S820 functions tocurate the content plurality and reduce the volume of content presentedto the user. The content to be curated and included in the content feedis preferably content from the plurality of content, but canalternatively be content associated with the geofence, contentassociated with the event, or any other suitable content. The set ofcontent is preferably curated after event feed aggregation, before eventfeed display to the user, but can alternatively be curated at any othersuitable point in the method. The set of content is preferablyautomatically curated, but can alternatively be manually curated. In onevariation, content focused on the event focus are preferably retainedwhile content focused on event attendees, participants, or bystandersare preferably removed from event feed. The content focus can bedetermined from metadata associated with the content, image analysis,content analysis, NLP, sentiment analysis, hashtags, explicit references(e.g., links) in the content, or through any other suitable method. Forexample, content having content that was generated by the front facingcamera of a mobile device can be automatically discarded, while contenthaving content that was generated by the back facing camera can beincluded. In a second variation, the event feed can be curated based onthe content type. For example, content including images and/or video canbe retained while content including only text can be removed. In a thirdvariation, selecting content for content feed inclusion can includeselecting content satisfying a set of conditions, such as media typeconditions (e.g., wherein only images or videos are selected), securitysetting conditions (e.g., wherein only public content is selected),user-specific conditions (e.g., wherein the content feed can includecontent generated by user accounts connected to the user accountassociated with the remote device), content parameter conditions (e.g.,wherein only content having more than a threshold number of views areselected), feature values (e.g., wherein content contributing heavily tothe event detection are selected), or selecting content satisfying anyother suitable set of conditions. The content can be selected based onthe content information stored in the content index, but canalternatively be selected based on the content itself, or selected inany other suitable manner. Alternatively, the event feed can remainuncurated, or be curated in any other suitable manner.

Curating the set of content can additionally include ordering thecontent within the feed, which can function to guide a user through anevent. In one variation of the method, ordering the content can includeordering the content according to the time that the content wasgenerated (e.g., the time the photograph was taken). In real-time feedgeneration, the new content can be included in the event feed if thegeneration time of the content is included in the plurality (e.g.,within an inclusion time threshold of the substantially instantaneoustime or within an inclusion time threshold of the generation time of thelast content included in the feed). The new content can be excluded fromthe event feed if the generation time of the content is outside of theinclusion time threshold of the substantially instantaneous time. In asecond variation of the method, ordering the content can includeordering the content according to location (e.g., along a path throughthe geographic region). For example, in an awards show, the event focuswill travel from the curbside, down the red carpet, and into the concerthall. This progression over location and time within the geographicregion will be reflected by the path traced by the highest contentdensity over time, and the content can be ordered based on the pathprogress (e.g., with content taken at the curbside ordered first, andcontent taken within the hall ordered last within the feed). However,the set of content can be ordered in any other suitable manner.Furthermore, the set of content can be curated using machine learningalgorithms to enable automatic feed creation or in any other suitablemanner.

Aggregating the selected content into a content feed S840 can includeaggregating the content into the content feed, the media of the contentinto the content feed, the content identifiers for the content into thecontent feed, or aggregating any other suitable content information intothe content feed.

Sending the content feed to the remote user device S860 can includesending the content to the remote user device, sending the contentidentifiers to the remote user device, or sending any other suitablecontent information to the remote user device. When a list of contentidentifiers are sent to the remote user device, the remote user devicecan retrieve the content from the source social networking system basedon the unique content identifier and populate the content feed based onthe retrieved content. However, the content feed can be otherwise sentto the remote user device.

The method can additionally include sending a notification about theevent to an entity, in response to event detection. The notification canbe selectively sent to entities based on the associated event category,geographic region associated with the geofence, or based on any othersuitable parameter. In one variation, the notification or event can besent to a first entity (e.g., endpoint) in response to the firstcategory probability exceeding the first category probability threshold,and the notification or event can be sent to a second entity (e.g.,endpoint) in response to a second category probability exceeding thesecond category probability threshold. The first and second entities arepreferably different entities, but can alternatively be the same entity.When an event is categorized as a first category, the event ispreferably sent to entities associated with the first category but notentities associated with the second category, and when the event iscategorized as the second category, the event is preferably sent toentities associated with the second category but not entities associatedwith the first category. However, the event can be sent to any othersuitable entity, whether or not they are associated with the determinedcategory. In one example, events categorized as news can be sent to newsentities, while events categorized as security violations can be sent tosecurity personnel. In another example, when the event is associatedwith both a news and a security violation category, notifications forthe same event can be sent to both news sources and security personnel.

The method can additionally include storing the event identifier andassociated feature values in association with the geofence, such thatthe event identifier and underlying feature values are persistent, evenif the content from which the feature values were determined is removedfrom the social networking system or otherwise inaccessible. The contentidentifiers of the underlying content plurality can additionally bestored in association with the event identifier. The event detectionsystem preferably stores the event identifier and associatedinformation, but another system (e.g., a social networking system, etc.)can alternatively store the event identifier and associated information.

An alternative embodiment preferably implements the above methods in acomputer-readable medium storing computer-readable instructions. Theinstructions are preferably executed by computer-executable componentspreferably integrated with an event detection system. The eventdetection system can include an event probability module configured todetermine the probability that an event was occurring within a geofenceat the time of content generation or posting based the values for afirst set of features determined based on geofence content, aclassification module configured to determine a set of labels orclassifications for an event based on the geofence content, and apost-processing module configured to resolve label conflicts and/ordetermine whether the event would be of interest to an entity based on asecond set of features. The computer-readable medium may be stored onany suitable computer readable media such as RAMs, ROMs, flash memory,EEPROMs, optical devices (CD or DVD), hard drives, floppy drives, or anysuitable device. The computer-executable component is preferably aprocessor but the instructions may alternatively or additionally beexecuted by any suitable dedicated hardware device.

Although omitted for conciseness, the preferred embodiments includeevery combination and permutation of the various system components andthe various method processes.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

We claim:
 1. A method for dynamic event extent determination,comprising: receiving content from a set of social networking systems;identifying a plurality of content, from the received content,associated with a geofence; determining a plurality of feature valuesfrom the plurality of content; reducing the plurality of feature valuesto a reduced plurality of feature values based on an event detectionmodel; using the event detection model, automatically detecting an eventwithin a geofence of the plurality of geofences based on the reducedplurality of feature values; in response to detecting the event withinthe geofence: including the geofence in an event region associated withthe event; determining a geographic extent of the event region,comprising iteratively: identifying a proximal geofence from among aplurality proximal geofences located proximal the geofence; analyzingthe proximal geofence for the event based on the reduced plurality offeature values; and in response to detecting the event in the proximalgeofence, including the proximal geofence in the event region; detectingan event termination based on another set of feature values from amongthe plurality of feature values; and associating the event region withthe detected event.
 2. The method of claim 1, further comprisingdetermining a baseline value for a feature from historic contentassociated with each geofence of the plurality; wherein automaticallydetecting the event comprises: detecting the event in response to thefeature value for the feature deviating from the baseline value for thegeofence.
 3. The method of claim 2, wherein the baseline value comprisesa baseline feature frequency for the respective geofence, whereindetecting the event comprises detecting the event in response to thefeature frequency exceeding the baseline feature frequency.
 4. Themethod of claim 3, wherein the content comprises posts, wherein thebaseline feature frequency comprises a baseline posting frequency forthe respective geofence, wherein detecting the event comprises detectingthe event in response to the posting frequency within the geofenceexceeding the baseline posting frequency for the geofence.
 5. The methodof claim 3, wherein the baseline feature frequency comprises a baselinekeyword frequency for the respective geofence, wherein detecting theevent comprises detecting the event in response to a keyword frequencywithin the geofence exceeding the baseline keyword frequency for thegeofence by a predetermined amount.
 6. The method of claim 5, whereinthe predetermined amount for the proximal geofence is determined basedon a size of the event region.
 7. The method of claim 1, wherein eachgeofence of the plurality of geofences represents a different physicalregion, each physical region having a common unit area.
 8. The method ofclaim 1, wherein the proximal geofence is contiguous with the geofencewithin the event region.
 9. The method of claim 1, wherein reducing theplurality of feature values comprises aggregating the selected contentinto a content feed; and further comprising sending the content feed, inassociation with an identifier for the event region, to a remote userdevice.
 10. The method of claim 9, wherein aggregating the selectedcontent into a content feed is repeatedly performed as new content isreceived from the set of social networking systems; and in response todetecting the event termination, ceasing content selection associatedwith the event.
 11. The method of claim 10, wherein detecting the eventtermination comprises: determining an event probability from the secondset of feature values; and detecting the event termination in responseto determination of the event probability falling below a thresholdevent probability.
 12. The method of claim 11, further comprisingmaintaining the event probability for a predetermined period of timeafter determination that the event probability fell below the thresholdevent probability.
 13. A method for dynamic event extent determination,comprising: for each of the plurality of geofences, determining abaseline value for a feature from historic content associated with eachgeofence of the plurality; receiving content from a set of socialnetworking systems; for each of a plurality of geofences: identifying aplurality of content associated with the geofence; and determining afeature value for the feature from the plurality of content; detecting afirst event within a first geofence of the plurality in response to thefeature value deviating from the baseline value for the first geofence;within a predetermined time window of detecting the first event,detecting a second event within a second geofence of the plurality inresponse to the feature value deviating from the baseline value for thesecond geofence; determining that the first and second event are acommon event; determining a third geofence encompassing the first andsecond geofences; and associating the third geofence with the commonevent; selecting content associated with the common event from theplurality of content; aggregating the selected content into a contentfeed; sending the content feed, in association with an identifier forthe event region, to a remote user device in response to receipt of arequest from the remote user device; receiving new content from the setof social networking systems; after detecting the first and secondevents within the first and second geofences, respectively: determininga second set of feature values for the third geofence from the newcontent; detecting an event termination based on the second set offeature values; and ceasing content selection associated with the event.14. The method of claim 13, wherein the baseline value comprises abaseline keyword frequency for the respective geofence, whereindetecting the event comprises detecting the event in response to akeyword frequency exceeding the baseline keyword frequency by apredetermined amount.
 15. The method of claim 13, wherein the contentcomprises posts, wherein the baseline value comprises a baseline postingfrequency for the respective geofence, wherein detecting the eventcomprises detecting the event in response to the posting frequencywithin the geofence exceeding the baseline posting frequency for thegeofence.
 16. The method of claim 13, further comprising categorizingthe first and second events with event categories, based on therespective feature values.
 17. The method of claim 16, whereindetermining that the first and second event are a common event comprisesdetermining that the first and second events are categorized with acommon event category.
 18. The method of claim 13, wherein detecting theevent termination comprises: determining an event probability from thesecond set of feature values; and detecting the event termination inresponse to determination of the event probability falling below athreshold event probability.
 19. The method of claim 18, furthercomprising maintaining the event probability for a predetermined periodof time after determination that the event probability fell below thethreshold event probability.